1. Field of the Invention
This invention is related to the field of lock mechanisms and, more particularly, to lock mechanisms with key storage.
2. Description of the Related Art
There are many situations calling for limited access to a home or business, for example, by custodial or repair persons. Often, one-time access may be all that is required. However, giving out a key typically grants unlimited entry and, therefore, compromises security. It would be desirable to have a means of securing the key following access to premises by designated persons.
Related prior art exists pertaining to secure storage and retrieval of a key. In many such systems the key is held in a key safe integrated into the door, from which the key may later be retrieved by means of a master key or externally accessible combination lock. U.S. Pat. No. 3,084,008 to Mallet, for instance, describes a type of key safe useful for real estate agents, in which a house key is kept within a key safe attached to the door of the house. The key safe is opened by means of a master key (obtained from the realtor) and the house key is tethered to the safe, so it cannot be removed from the premises. However, this invention is obviously not suitable for situations in which it is necessary to loan out the key.
Another related device is described in U.S. Pat. No. 4,615,281 to Gaston, in which an electronic combination lock provides entry to a key safe within the door. This method also suffers from drawbacks that render it unsuitable for the types of use described in the preceding paragraph. In order to grant someone access to the key safe, it would be necessary to give him or her the combination. But it would then be necessary to change the combination; otherwise that individual would continue to have access to the safe after the intended period. Furthermore, loss of power would render the combination lock to the key safe inoperative, which could result in the user being locked out.
The problems outlined above are in large part solved by a locking mechanism with an integrated keyslot as described herein. The mechanism comprises a lock assembly, within which is a slot. The slot is accessible from the exterior surface of the door and connects to a chute, through which the key slides when dropped into the slot. The chute deposits the key into a receptacle on the interior surface of the door, in which it is retained until the owner can retrieve it. In one embodiment, a magnet within the receptacle serves to draw the key down the chute and capture it.
A method is also contemplated for securing a key within a door lock, such that the key may be deposited from the outside after locking the door, and is ensconced within a receptacle accessible only from the inside.
It is often necessary to loan out a key in order to grant someone limited access to a home or business. It is believed to be advantageous to have a means for safely returning the key immediately after use, thereby reducing the risk that the key could become lost or stolen.